Method of manufacturing ribbed dome hollow head valves



2'39, i arfio R THQREN ET AL Zy-i-lljwi METHOD OF MANUFACTURING RIBBED DOME HoLLc-w HEAD VALVES Original Filed Aug. 30, 1940 2 Shets-Sheet l 7. Theodore E. T/Ioren- Pa u./ F. Jb/mJo/z.

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Y 2 1946- T. R. THOREN ET AL 2,411,754

METHOD OF MANUFACTURING RIBBED DOME HOLLOW HEAD VALVES Original Filed Aug. 50, 1940 2 Sheets-Sheet 2 25 .752 ADJ-'5 Theodore R. Tho/"en.

i Patented Nov. 26, 1946 METHOD OF MANUFACTURING meson DOME HOLLOW HEAD VALVES Theodore H. Thoren and Paul P. Johnson, Cleveland, Ohio, assignors to Thompson Products, Inc.-, a corporation of Ohio Original application August 30, 1940, Serial No. 354,778. Divided and this application January 30, 1943, Serial No. 474,112

This invention relates to the reinforcing of hollow head valves. 7

More specifically the invention relates to the production of hollow poppet valves with one or more internal ribs formed on the dome of the valve head to better resist higher external pressures acting on the valve head.

This application is a division of our copending application Serial No. 354,778, filed August 30, 1940, now Patent No. 2,328,512, granted August 31, 1943.

Increasingly higher compression ratios, explosion pressures and motor temperatures in internal combustion engines are causing collapse of hollow head valves. This collapse usually occurs in the top wall or dome of the valve directly above the head cavity. While the domes of the valves could be made thicker to better resist the tremendous pressures to which they are subjected, the use of more metal in the valve head is undesirable for a number of reasons. For example, the resulting ValVes will be heavier, the heat retention in a thick, solid metal wall is greater than in a thin, solid metal wall, and the head cavity would have to be made smaller, thereby reducing the amount of coolant such as metallic sodium that could operate in the cavity for dispersing the heat away from the head of the valve.

According to the present invention, the heads of hollow poppet valves are stiffened by means of one or more internal ribs. These internal ribs are formed integrally on the inner wall of the valve head and act as a reinforcing strut for the dome ofthe valve to reinforce the same against collapse without, however, resulting in the disadvantages of a thick-walled dome. The ribs, according to this invention, are preferably formed by die pressure during the course of manufacturing the hollow poppet valve.

It is, then, an object of the invention to make hollow head poppet valves with reinforcing ribs stiffening the valve heads.

Another object of the invention is to increase the resistance of hollow valve heads against collapsing under external pressures by forming therein localized reinforcing ribs depending from the inner wall of the dome of the valve.

Another object of the invention is to make hollow valves having increased resistance against collapsing by external pressures without increasing the thickness of the valve walls.

Another object of the invention is to form ribbed dome hollow head valves by die pressure operations.

3 Claims. (01. 29-15617) A specific object of the invention is to provide a method for forming integral ribs in the domes of hollow head valves out of metal originally present in the wall of the dome.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which disclose preferred embodiments of the invention.

On the drawings:

Figure 1 is a vertical cross-sectional view taken through a metal billet forming a, blank.

Figure 2 is a vertical cross-sectional view of the blank shown in Figure 1 after the interior of the blank has been machined.

Figure 3 is a vertical cross-sectional View with parts in elevation illustrating one method of forming a rib 0n the dome of the blank shown in Figure 2.

Figure 4 is a vertical cross-sectional view, with parts in elevation, taken along the line IV--IV of Figure 3.

Figure 5 is an axial cross-sectional view of a partially formedvalve body made from the blank shown in Figures 3 and 4.

Figure 6 is a vertical cross-sectional view, with parts in elevation, showing a swaging operation for necking down the valve body shown in Figure 5.

Figure 7 is a vertical cross-sectional view of a valve body formed from the body shown in Figure 6 and having a solid or collapsed stem portion.

Figure 8 is aview similar to Figure 7 but illustrating an enlarged upset end portion on the tem.

Figure 9 is a vertical cross-sectional view of a finished hollow valve made from the body illustrated in Figure 8.

Figure 10 is a fragmentary longitudinal crosssectional view of a rib dome valve according to this invention.

Figure 11 is a cross-sectional view taken along the line XIXI of Figure 10.

Figure 12 is a cross-sectional view taken along the line XII-XII of Figure 10.

Figures 13 to 16 inclusive are inside face views of various types of ribbed domes for valve heads obtainable according to this invention.

Figure 17 is a vertical cross-sectional View taken along the line XVII-XVII of Figure 18 lllustrating another method of forming an internal rib in the dome of a hollow head valve body.

Figure 18 is a cross-sectional view, with-parts in elevation, taken along the line XVIII-XVIII oiFigure l7. 4

Figure 19 is a cross-sectional view taken along the line XIX XIX of Figure 14.

As shown on the drawings:

In Figure 1 the reference numeral I8 designates generally a blank formed from a solid metal slug by piercing the same to form therein a blind bore I I having an inclined blind end I2. A dome head I3 of increased diameter is also formed on the blank. While the blank I is preferably formed by piercing or forging operations, it should be understood that the same can be cast into the form shown in Figure 1.

In Figure 2 the blank III is shown in a machined state wherein the bore II is machined to provide a blind end 52a of a flatter contour than that originally present at I2 in the pierced blank. The shallow concave contour I20; is substantially maintained during the entire process of fabricating the valve.

In Figures 3 and 4 the machined blank Iii is illustrated as mounted in a die I4 formed in two half-sections I ia and Nb held together by means of bolts such as I5 and, when bolted together, defining a cavity is having the contour of the machined blank It and snugly receiving the blank therein as shown. Aplunger I1 having a grooved end Ilais forced into the bore II of the blank It and pressed against the head I3 of the blank under great pressure to cause metal to flow from the head into the groove Ila of the plunger and thus produce a rib I8 across the inner face of the domed valve head. This rib I8 stiffens the dome and reinforces the same against collapsing by external pressures.

The ribbed blank is then removed from the die It and subjected to alternate swaging and extrusion operations for forming a valve body I9 shown in Figure 5. The valve body I 9 has a partially formed stem portion 243 of reduced diameter; The valve body I9 is next subjected to a necking down swaging operation as shown in Figure 6 wherein the stern portion adjacent the I 3 is necked down as at Zlla by means of swaging dies 2!. The necked down valve body It is next subject to extrusion operations which reduce and collapse the necked down stem portion 2% into a solid reduced stem 2! of re-- du ed diameter as shown in Figure 7. The valve body 22 thus produced has a solid stem 2| and a hollow head I3. The end of the solid stem 2| is next upset as shown at 21a in Figure 8 to provide a thickened portion thereon.

The valve body 23 of Figure 8 is next machined and axially drilled to produce the finished valve 21 shown in Figure 9. The stem portion 2| of the body 23 is drilled to provide the bore 24 having a tapered end Eta communicating with the cavity in the head I3 of the valve. The thickened portion Zia of the blank 23 is pressed in to close the open end of the bore 24 as at 26 and the closed portion is then bored to receive a sealing plug 28. Metallic sodium or other coolant C is placed in the cavity provided by the bores 24, 2 411 and the head cavity 25, and is sealed in these cavities by means of the plug 28. An annular groove 25a is provided around the end of the stem for receiving a valve spring retainer.

The finished valve 2? shown in Figure 9 thus has a hollow stem and head and the dome of the head has an internal rib i8 extending thereacross toresist collapsing forces applied externally on the dome.

The valve 27, as best shown in Figures 10 to 12, has a comparatively thin domed head I3 and this thin head is reinforced by the internal rib valve head cavity 25.

I8 which bridges a substantial portion of the dome between the side walls. This bridging rib so reatly stiffens the dome that very thin walls can be used in the dome.

The valve head is preferably grooved around the side. periphery thereof to receive a bearing ring 29. This ring 29 serves as the seat for the valve and can be made of a wear-resisting alloy different from the metal making up the valve body. The ring 29 can be welded in the groove around the valve head or can be puddled from moltenmetal into this groove.

As shown in Figure 10, the rib I8 is longitudinally curved and merges at its ends I8a into the dome head I3 with a gently curved contour. The rib I8 does not extend to the sides of the As shown in Figures 11 and .12, the rib I 8 is also curved in transverse cross section to provide a somewhat rounded contour ISb. This transverse contour readily lends itself to die pressure formation and at the same time gives a very efiicient stiffening effect to the rib.

In Figures 13 to 16, the reference numerals Iiia, I32), I30 and I311 represent the inner faces of valve heads or domes similar to the heads or domes I3 described in Figures 1 to 12. The dome in Figure 13 has a single rib 3B integrally formed thereon and depending into the interior of the valve across the entire dome or head. In other words, the rib 3i differs from the rib I8 in that it bridges the entire span of the dome from s de to side and through the center of the head. The rib 30 preferably has the general transverse contour I81) of the rib I3 and can, if desired, be longitudinally curved like the rib I8 to merge into the side walls of the valve along a gently sloping line.

In Figure 14 the valve head .or dome I3b is provided with a rib 3| in the shape of a Greek cross. This rib 3! has four legs of equal length merging in the exact center of the dome and extending to the side walls of the valve. The rib 3! can be transversely shaped as at 3Ib (Fig. 19) like the rib I8 and the legs of the rib 3| can also be curved longitudinally as at 3Ia. (Fig. 19) like the rib I8.

In Figure 15 the valve head or dome I30 is provided with a rib 32 of checkerboard design. In other words the rib 32 has parallel legs 33 and 34 intersecting with another pair of parallel ribs 35 and 36 at right angles to the first mentioned pair. The ribs 33, 34, 3-5 and 36 are equally spaced from the center of the dome I30 and a square such as 3? is thus provided in center of the valve dome bounded by square segments 38; The extremities of the ribs 34 to 36 mergeinto the side walls of the valve and each rib can have a transverse contour similar to the contour I 8?) of the rib I 8.

In Figure 16 the valve head or dome has two parallel ribs 39 and 4!! equally spaced from the center of the dome and bridging the entire span of the dome.

The forms of ribs shown in Figures 13 to 16 can be made in the same manner illustrated in Figures 3 and 4 merely providing the plunger I! with a groove or grooves capable of producing the illustrated patterns in Figures 13 to 16.

In order to extend the ribs to the side walls of the valve head, the groove in the plunger I! would be extended to the outer periphery of the plunger.

In Figures 17 and 18 there is illustrated another method of forming a rib on the'"head or e2, a pierced cylindrical cavity E3, and an enlarged head cavity ii. The body it differs from the blank it shown in Figures 1 and 2 in that the head cavity it is already formed larger than the cavity it. The body it compares generally with the body i9 shown in Figure 5 prior to the last forging operation which further reduced the stem portion 26.

The body M is seated on a stationary punch 35 having a rib forming groove lba in the upper end thereof. The end of the punch having the groove dbatherein receives the dome 42 of the body thereon.

A movable punch 46 having a tongue liia projecting from the lower end thereof is forced down on top of the dome G2 with the tongue tea in alignment with the groove 45a of the stationary punch. The tongue 45o. then moves metal in the dome or head into the groove the of the stationary punch to form a rib il similar to the rib iii described above in connection with Figures 3 to 12.

Since the valve head cavity M is larger than the cavity lfi the rib ti formed by this movable and stationary punch method cannot extend to the side walls of the valve head inasmuch as the stationary die d5 through the smaller cavity '43.

The tongue 48a of the movable plunger 55 will leave a recess es in the outer wall of the valve head but this can be removed in subsequent manufacturing operations. For example, the head of the body ll can be sufiiciently thick at this stage of the valve forming operation so that metal can be removed to a depth greater than i the depth of the recess till thus leaving a smooth unbroken surface on top of the body.

In the process illustrated in Figures must be small enough to fit 3 and 4,;

the rib portion of the valve head is actually thicker than the rest of the head wall since the enveloping die M for the valve blank permits gathering of the metal to form the rib, whereas in the method illustrated in Figures 1'? and 18 the metal is only pushed into the groove of the stationary plunger to formthe rib. However if thehead metal is then removed down to the bottom of the recess 43, the rib portion of the resulting valve will be thicker than the rest of the head wall. f 1

From the above descriptions it should be understood that this invention now provides for the stiffening and head. The ribbed hollow head valves of this invention can thus be made with the usual thin walls and at the same time the valves will resist greater external presstrengthening of the heads or I domes in hollow poppet valves by adding a mini mum of metal in the valve details of construction may pet valves including 'of the end wall and .is raised on the inner sures than heretofore. The inwardly projecting ribs formed on the valve heads or domes according to this invention have a secondary function of providing an increased area on which the coolant in'the valve can act so that heat transfer between the valve head and the coolant is enhanced.

It will, of course, be understood that various be varied through a wide range without departing from the principles of this invention and it is,'therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

We claim as our invention:

1. The method of stiffening the domes of hol low head poppet valves which comprises snugly confining the exterior of a hollow metal blank having a blind cavity therein bottomed by a solid wall, exerting pressure simultaneously on all of said solid wall with the exception of a localized central transversely extending portion of the inner face of the wall, and causing wall metal to flow to said portion in the blind cavity for forming a thickened solid rib on said wall in the cavity.

2. The method of stiffening the domes of hollow head poppet valves which comprises abutting the outer end face of a hollow metal valve blank with a member having continuous surface contact over the entire end face, abutting the inner end face of said blank with a rigid member having simultaneous contact with said inner face except at a localized rib-shaped recessed portion of the member, and squeezing said blank between said members under sufficiently high pressure to flow metal from the blank into said recess for forming an integral solid rib depending into the hollow interior of the blank and being thicker than the end wall of the blank.

3. In the method of making hollow head popthe formation of a cupshaped metal blank, a swaging of the blank to neck down the side walls thereof adjacent the closed end thereof and the extrusion of the side wall from the necked-down portion thereof, the improvement of the steps of squeezing the end wall of the blank prior to the swaging operation between pressing surfaces including a surface having simultaneous contact with the inner face v oftheend wall except at a localized rib-shaped recessed portion converging away from the end distance at the axial center continuing the squeezing operation until an integral solid stiffening rib face of the end wall with its thickest portion at the center of theend wall.

wall to a maximum THEODORE R. THOREN. PAUL P. JOHNSON. 

